Needle looms



Feb. 17, 1970 W. C. ARNOLD NEEDLE LOOMS Sheets-Sheet 1 Filed NOV. 15)1967 m MW 111 Fin. 2- v WILLIAMCARUOLANVENTOR:

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NEEDLE LOOMS Filed Nov. 15, 1967 3 Sheets-Sheet 2 E Ill 2 Bl s 2 CYCLETIME 360 Fla. 4.

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Feb. 17, 1970 w. c. ARNOLD NEEDLE Looms med Nov. 15. 1967 3 Sheets-Sheet5 CYCLE. TIME FILI.

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United States Patent 3,495,632 NEEDLE LOOMS William C. Arnold,Burton-on-Trent, England, assignor to Bonas Bros. Weavematic Looms(England) Limited, a corporation of Great Britain Filed Nov. 15, 1967,Ser. No. 683,216 Int. Cl. D03d 47/44 US. Cl. 139-124 11 Claims ABSTRACTOF THE DISCLOSURE A needleloom having the normal operating parts, namelyreed, weft inserting needle and latch needle, in which the motions ofthese parts are controlled by pairs of phased eccentrics synchronised t0the loom speed. The speed of one of the eccentrics being arranged to betwice that of the other to give the required motion to a linkage whichincludes a bell crank lever and bridge link connecting the eccentricsand either reed weft inserter needle or latch needle.

This invention concerns smallware looms of the kind in which the weft isinserted by a needle, hereinafter called needle looms.

In needle looms of the generally accepted type it has been usual tocontrol the operating movement of parts such as the weft insertingneedle, the beat-up reed, the selvedge knitting needle (in most but notall cases a latch needle) and the locking thread inserting member bymeans of a lever system actuated by a cam follower moving in a camgroove machined in the face of a cam.

When it is desired to operate the machine at high speed it is found thatthe use of cams is a serious disadvantage since a high load is imposedon the cam track and the follower and thus the cam track and thefollower must be of substantial proportions; this in turn necessitatesthe provision of a large cam so that cam track cutting errors may beobviated, these errors being most likely to occur when the minimumradius of curvature of the cam track relative to the width of the trackbecomes small. It also follows that high speed operation results in highinertia and high rate of wear in the cam track and on the cam follower.

The principal object of the present invention is to provide a drivingmeans for a needle loom which is capable of operation at high speed anddoes not suffer from the above outlined disadvantages.

According to the present invention a needle loom operating mechanism forcontrolling some or all of the operating movements required for weavingand for the knitting of one or both selvedges is characterised in thatthe operating movements for one, some or all of the members effectingthe weaving and/or knitting is derived from pairs of phased eccentricbearings in which one member of the pair is adapted to rotate at ahigher velocity than the other, the said higher velocity being amultiple of the velocity of the other member of the pair, there beingindividual connecting rods journalled one on each of the said eccentricbearings, the free ends of said connecting rods being connected by abridge link which carries at a point intermediate its ends aconstraining member adapted to control weaving and/or knitting motions,the linkage as a whole comprising a seven bar linkage sysem.

Preferably the velocity of the fast moving member of the pair is twicethat of the other member of the pair.

The invention will be described further, by way of example withreference to the drawings in which:

FIG. 1 is an end elevation of part of a needle loom made in accordancewith the invention,

FIG. 2 is a plan view of FIG. 1,

3,495,632 Patented Feb. 17, 1970 FIG. 3 is a view corresponding to FIGS.1 and 2 illustrating in addition the linkage used to control the reed ofa needle loom,

FIG. 4 is a graph of the motion obtained by the mech anism of FIG. 3.

FIG. 5 is a modification of the mechanism illustrated in FIGS. 1, 2 and3,

FIG. 6 is a graph of the motion obtained by the mechanism of FIG. 5,

FIG. 7 is a view of a further modification of the mechanism and,

FIG. 8 is a graph of the motion obtained by the mechanism of FIG. 7.

Referring firstly to FIGS. 1 and 2 it will be seen that there areprovided two driving shafts 1 and 2, mounted transversely of a loomframe. The shafts 1 and 2 are arranged to rotate in opposite directions.One shaft is arranged to rotate at a speed twice that of the other.Carried on each of the shafts 1 and 2 are phased eccentrics 3, thedegree of eccentricity and phasing being the subject of exactconsideration. On the eccentrics 3 are journalled connecting rods 4, oneconnecting rod from each eccentric 3 being together considered a pair.At least one pair of connecting rods are provided for each operatingmovement required. If desired the direction of rotation of the shafts 1and 2 can be the same.

The connecting rods are tied together at their little ends by means of abridge link 5 and from a point, preferably but not necessarily, themidpoint of this link connection is made with the end of one arm 8 of arocking bell crank lever 6, or constraining member. The lever 6 ispivoted on a fixed shaft 7, located outside the line of action of theconnecting rods 4. The other arm 9 of the rocking lever 6 projects in anattitude such as to provide the means of driving the appropriate loomelement, either directly as shown for example in FIGS. 3, 5 and 7, orindirectly by means of push rods and additional levers not illustrated.

In the above description reference has been made generally to thedisposition of parts of the loom which, by slight modification of thephasing of the eccentrics and the distances between pivot points andcentres can be utilized for obtaining various motions illustrated inFIGS. 4, 6 and 8.

The linkage referred to above comprises, with the loom frame, what isknown as a seven bar geared linkage and the seven bars of the mechanismdescribed are as follows:

Bar 1loom frame Bar 2-primary eccentric (preferably the one rotating atmachine speed) Bar 3secondary eccentric Bar 4primary connecting rod Bar5secondary connecting rod Bar 6bridge link Bar 7constraining memberReferring now to a first specific use of the mechanism generallydescribed, and with reference to FIGS. 3 and 4, when used to control themovement of the loom reed it will be seen that the projecting arm 9 ofthe rocking lever 6 is used as one member of a parallel motion linkageas shown in FIG. 3. In addition to the arm 9 a trailing link 10pivotally mounted to the loom frame 11 is provided together with aconnecting link 12. The link 12 forms a bridge between the rocking lever6 and the trailing link 10 and serves to carry the reed 12a. Anoscillatory movement of the rocking lever 6 about its axis shaft 7causes the reed 12a to move forwardly to beat-up an inserted weft loopand then return to a safe position, when the weft of the next loop canbe inserted. It has been customary to accord to the reed 12a a motionsuch that On its return to the safe position it remains completelystationary during a pre-determined period until it commences to move tothe beat-up position. The motion provided by the use of the previouslydescribed double eccentric shafts 1 and 2 however, will, because ofinherent characteristics, give, in the safe region a small reciprocatorymovement. The degree of reciprocation is, however, quite small inrelation to the total travel of the reed and results in a period whichis substantially a dwell period. This motion is graphically illustratedin FIG. 4 and the phasing of the eccentrics is designed for thispurpose.

The mechanism referred to in FIGS. 1 and 2 is again illustrated in FIG.5 and in this case the modification made enables the motion obtained(and graphically illustrated in FIG. 6) to be utilized for controllingthe movement of a latch needle 13 used to knit the selvedge of a woventape of fabric. In this case the projecting arm 9 of the rocking lever 6causes reciprocation of a slide on which is carried for example, theconventional hosiery latch needle 13. At the end of the arm 9 there isprovided a square sided block 14 pivotally mounted on a pin not shown.

A fork piece 16 carried on a sliding rod 17 embraces this block 14 whichis capable of sliding therein to accommodate the change in height whichoccurs as the tip of the rocking lever arm 9 swings through the arc. Therod 17 slides in bushes 18 and is restrained from turning about its ownaxis by providing a hardened guide strip 19 which locates in a groove 20machined in an extension of the fork piece 16. At its extremity the rod17 carried a needle holder 21 into which the latch needle 13 is adaptedto be secured.

The motion provided can be substantially as graphically illustrated inFIG. 6 and is again derived from suitable phased eccentrics. Variationof the motion is possible. It will be seen from FIG. 6 that the knittingneedle is given an overall motion arranged to ensure that the needleinstead of remaining stationary during the major part of the operatingcycle it is caused, on its return stroke after casting off a loop, totravel beyond the point at which the hook is in line with the weftinserter needle. This additional travel ensures that the weft loop whichhas been newly drawn and is lying around the needle is caused to sliprapidly down and off the latch and onto the shank of the needle in apositive manner thus overcoming the slight impediment to transferoffered by the broadened tip of the latch. The latch needle then startsagain on its forward stroke without any dwell period, coming to restafter a short return movement and remaining stationary during the timewhilst the weft inserter passes across the throat of the latch needle,and before continuing its movement when its hook will take the newlyinserted weft pick and knit it through the previous loop in theconventional manner. Modification of the phasing of the eccentricbearings 3 would produce a variation in the obtained motion which wouldenable the knitting form to be changed if desired.

In a third modification of the arrangement of FIGS. 1 and 2, asillustrated in FIG. 7 there is provided a means for obtaining the motionillustrated graphically in FIG. 8. This motion is used to control themovement of a device which introduces into the selvedge a locking threadarranged to prevent unravelling of the loops of the selvedge and in thearrangement shown, forms part of a modified bell-crank lever 6. Thebell-crank lever 6a is pivoted outside of the line of action of theConnecting rods such that one arm 8a is connected to the bridge link 5of the pair of connecting rods 4 as previously described. The other arm9a, which carries a thread guide eye 22, projects in such a manner thatas the lever 6a oscillates about the shaft 7a due to the motion of theeccentrics 3, the thread guide eye 22 is caused to move fore-andaft ofthe loom and at the same time to rise and fall due to the arcuatemovement of the lever arm 90. In

a preferred, timing of the eccentrics 3 the additional locking thread(not shown) is thereby lifted as the latch needle moves away from theguide eye 22 and falls as the latch needle approaches it. The motion issubstantially as shown in the time/distance graph and is derived fromsuitably phased eccentrics.

The weft inserting needle of a needle loom can be caused to operate froma pair of eccentrically mounted connecting rods having a motionsubstantially as shown in FIG. 4.

Although all the weaving and selvedge knitting operations of a needleloom have been described as being actuated from phased eccentrics it isnot essential that all the movements should be so obtained. For example,any one or more of the desired movements may be derived fromconventional mechanisms, such as cams, whilst others are derived fromphased eccentrics as described.

What is claimed is:

1. A drive mechanism for a loom which produces a beat-up motion, aselvedge needle motion, and is adapted to produce a selvedge threadpresenting means motion; which mechanism comprises a loom frame, atleast one pair of phased eccentric members, means for rotating onemember of said pair at a velocity in excess of the other member, theeccentrics being mounted on rotatable rods journalled insaid frame;connecting rods journalled one on each of said eccentrics; a bridge linkjournalled to each of said connecting rods; a constraining memberconnected to said bridge link intermediate its ends and journalled onsaid frame for controlling said motion; the loom frame, the pair ofphased eccentric members; the connecting rods, the bridge link and theconstraining member comprising as a whole a seven bar linkage system.

2. A drive mechanism as described in claim 1 in which said one eccentricmember is rotated at twice the speed of said other eccentric member.

3. A drive mechanism as described in claim 1 in which the rotatable rodsareparallel spaced-apart shafts provided for receiving said eccentrics.

4. A drive mechanism as described in claim 1 in which the constrainingmember controls a loom reed beat-up.

5. A drive mechanism as described in claim 1 in which the constrainingmember is a bell-crank member pivotally mounted on the loom frame, therebeing a reed on said loom and a connecting link between said bell-cranklever and said reed.

6. A drive mechanism as described in claim 5 in which a trailing linksupports the end of said connecting link at its end remote from saidbell-crank lever.

7. A drive mechanism as described in claim 5 wherein said bell-cranklever is slidably and pivotally connected to a selvedge knitting needleoperating rod.

8. A drive mechanism as described in claim 1 in which at least one pairof phased eccentrics is provided to control the movement of a weftinserting needle.

9. A drive mechanism as described in claim 1 in which at least one pairof phased eccentrics is provided to control the movement of a selvedgeknitting needle.

10. A drive mechanism as described in claim 1 in which said pair ofphased eccentrics is provided to control the insertion of a selvedgelocking thread.

11. A drive mechanism for controlling a selvedge needle, which mechanismcomprises a loom frame; a pair of phased eccentrics rotatably mounted onrods which are journalled in said loom frame; means to rotate one ofsaid pair at a velocity in excess of the other; connecting rodsjournalled one on each of said eccentrics; a bridge link journalled tosaid connecting rods; a constraining member connected to said bridgelink intermediate its ends and journalled on said frame for controllinga selvedge needle, said constraining member being a bell-crank leverpivotally mounted on the loom frame, a sliding pivoting connectionbetween said bell-crank lever and a selvedge knitting needle operatingrod, said sliding pivoting connection including a forked piece on saidselvedge knitting 5 needle operating rod, a pivotally mounted connectionpiece on said bell-crank lever connecting with said forked piece andbushings for mounting said selvedge knitting needle operating rodrestraining said operating rod to reciprocate.

References Cited UNITED STATES PATENTS 2,013,230 9/1935 Best 139-1247/1951 Robinson 139-124 11/1962 Piazzolla et a1. 139-124 5/1967Gustavson 139-124 5 HENRY S. IAUDON, Primary Examiner US. Cl. X.R.

